# WHATPORT(4003)

## NAME

port 4003 — pxc-splr-ft (IANA registration) — An IANA name with no public protocol behind it — whatever is listening here picked the port itself.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA registers 4003 as pxc-splr-ft, one of a block of pxc-* names running from 4002 to 4007 that carries no contact, no reference and no published protocol description. There is no well-known software that binds 4003 by default and scanners see it only rarely. In practice a listener here is an application that was told to use a free port, not the registered service.

## EXPOSURE

**Expose with care.** The verdict belongs to whatever actually answers — treat an open 4003 as an unidentified service and fingerprint it before deciding.

## CHECK

```sh
nc -vz -w 3 TARGET 4003
```

## SEE ALSO

- iana — [IANA port registry — 4003 (pxc-splr-ft)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=4003) (iana.org)

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HTML: <https://whatport.net/4003/> · JSON: <https://whatport.net/4003.json> · full dataset: <https://whatport.net/ports.json>